Re: [PATCH v5 02/12] dax: introduce IS_DEVDAX() and IS_FSDAX()

[Christoph Hellwig <hch@xxxxxx>]

> +static inline bool IS_DEVDAX(struct inode *inode)
> +{
> +	if (!IS_ENABLED(CONFIG_DEV_DAX))
> +		return false;
> +	if ((inode->i_flags & S_DAX) == 0)
> +		return false;
> +	if (!S_ISCHR(inode->i_mode))
> +		return false;
> +	return true;
> +}
> +
> +static inline bool IS_FSDAX(struct inode *inode)
> +{
> +	if (!IS_ENABLED(CONFIG_FS_DAX))
> +		return false;
> +	if ((inode->i_flags & S_DAX) == 0)
> +		return false;
> +	if (S_ISCHR(inode->i_mode))
> +		return false;
> +	return true;

Encoding the is char device or not thing here is just nasty.  I think
this is going entirely in the wrong direction.